The invention relates to a selector for an automatic gear-changing device of a motor vehicle.
A known selector device of this generic type, for a two-speed automatic gearbox of a motor vehicle driven by an electric motor (with or without support by a gas turbine) is disclosed in the Journal "Auto, Motor und Sport", No. 20, 24 September 1993, Pages 139 and 141. In this device, the usual automatic gearbox selector lever is replaced by a rotary switch which can be actuated manually into four significant angular positions which are associated with the positions P, R, N and D of the automatic gear-changing appliance.
The object of the present invention is to simplify the operation of a vehicle equipped with such a selector device while ensuring security against theft.
This object is achieved by the selector device according to the invention, in which the automatic gear-changing appliance of the gearbox is positively retained in the P position when the combined key unit is withdrawn, so that the current supply for electrical consumption units and engagement of the starter are further blocked. On introduction of the combined key unit into the gate of the selector cylinder unit, the gear-changing appliance remains in the P position but the voltage source and the starting motor are unblocked. The vehicle is made ready for operation by rotating the selector cylinder unit into the N position by means of the combined key unit. If the selector slide unit is now pressed forward into the D position by means of the combined key unit, the gear-changing program for the forward gears is activated. The gear-changing appliance is brought into the position for the reverse gear by pressing the selector slide unit rearward into the R position by means of the combined key unit.
Substantial advantages are achieved by the invention. First, ergonomically unambiguous and logical handling is provided for the operation of the lock, ignition and starter. Also, the operational reliability is increased, specifically by ergonomic rational control of forward and rearward travel. Forward motion of the combined key unit is associated with forward travel, and rearward motion of the combined key unit is associated with rearward travel. The security of the parked vehicle is ensured by the parking brake interlock, thus providing increased security against theft in comparison with a conventional steering column lock. The previously usual ignition and steering column lock becomes unnecessary, thus increasing passive safety (knee impact on the ignition and steering column lock). The selector device is also characterized by small dimensions.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.